Hydrodesulfurization catalysts based on supports prepared from rehydratable alumina

Abstract

Disclosed is a method for producing a hydrodesulfurization catalyst and the catalyst produced thereby. The HDS catalyst is prepared by solution impregnation of an alumina catalyst support which has been made from a rehydratable form of alumina.

We claim: 
     
       1. A method of preparing hydrotreating catalysts for catalytic hydrodesulfurization of petroleum, having activated alumina supports, comprising: preparing a partially dehydrated, rehydratable alumina by flash calcining Bayer process hydrated alumina;   rehydrating said partially dehydrated alumina with water which contains acid at pH below 7 at rehydration temperature, for the time needed for rehydration;   solidifying the rehydrated alumina;   mulling the solidified rehydrated alumina with sufficient water to make a mulled mixture suitable for particle forming; forming particles of desired size and configuration from the mulled mixture;   drying the formed alumina particles and then calcining same by heating to calcining temperature;   impregnating the calcined particles with liquid solutions of soluble compounds which are thermally decomposable to oxides of cobalt or nickel and to oxides of molybdenum or tungsten; and   activating the impregnated alumina particles by calcining heat treatment to form hydrotreating catalysts.   
     
     
       2. The method of claim 1 including a washing step to remove soda impurities from the alumina. 
     
     
       3. The method of claim 2 wherein said forming comprises extruding an aqueous mix of the rehydratable alumina composition. 
     
     
       4. The method of claim 2 wherein said catalyst support particles are formed in the shape of beads. 
     
     
       5. A hydrotreating catalyst prepared according to the method of claim 1. 
     
     
       6. A hydrotreating catalyst prepared according to the method of claim 3. 
     
     
       7. A hydrotreating catalyst prepared according to the method of claim 4. 
     
     
       8. A hydrotreating catalyst prepared according to the method of claim 2. 
     
     
       9. The hydrotreating catalyst prepared according to the method of claim 1 wherein the promoters in the calcined hydrotreating catalyst consist of 2-6% by wt of the catalyst of a member selected from CoO and NiO and 6-24% by wt of the catalyst of a member selected from MoO 3  and WO 3 . 
     
     
       10. The method of claim 2 including a curing step to harden the molded catalyst support forms. 
     
     
       11. The method of claim 10 wherein said curing step is a stream treatment step. 
     
     
       12. A hydrotreating catalyst prepared according to the method of claim 10.